Suspected Islamist gunmen freed German diplomat Rainer Berns unharmed overnight, two months after he was taken hostage in Yemen, officials said Monday.

Berns, 55, the commercial attache at the German embassy, was brought to the capital Sanaa by police helicopter on Monday morning and taken home after his midnight release.

"We thank the Yemeni authorities for their wisdom in earning the release of Rainer Berns and his return safe and sound," a diplomat at the German embassy told AP.

Tribal leaders managed to get him released peacefully," one official told AFP by telephone from Maarib province, some 170 kilometers (100 miles) east of the capital Sanaa.

"He is well but he needs a rest after his long period in captivity," the official added.

"The hostage was freed without any conditions," a police officer said. "The security forces will keep up the hunt for the kidnappers to arrest them and bring them to justice."

The exact circumstances of the release were unclear, as was the identity of the kidnappers who asked for a million-dollar ransom.

A tribal dignitary told AFP that the "abductors come from the Al-Zaidi tribe whose members are all supporters of the Islamic Jihad," a hardline Yemeni group. At least one of the men, named as Mohammad Zaidi, had fought in Afghanistan, he said.

A Western diplomat last month said Berns had been abducted by an "Islamist terrorist group," rather than by a tribe.

Berns, who was abducted from his car in Sanaa on July 27, had been held in Serwah, 30 kilometres (18 miles) east of Maarib.

He had managed to send a message to his embassy last week saying he had been forced by his kidnappers to walk a long distance in a mountainous area to another detention location far from security forces.

Kidnappings are common in Yemen by heavily armed tribesmen seeking money or concessions from the government or oil companies. More than 200 foreigners, mostly westerners, have been seized since 1991.

Almost all hostage-takings have been resolved peacefully through mediation, although three Britons and an Australian died in December 1998 when security forces stormed the hideout of a hardline Islamist group -- SANAA (AFP)